Structural Correlates of Depressive Symptoms in Prodromal Alzheimer’s Disease.

ABSTRACT

Background/Aims: We conducted a cross-sectional study to investigate the structural magnetic resonance imaging correlates of depressive symptoms at the initial clinical stages of Alzheimer’s disease (AD). Methods: Subjects aged 65 or more were categorized as prodromal AD (n=18), mild AD (n=35), or normal cognition (n=76). Depressive symptoms were measured by means of the 15-item abridged version of the Geriatric Depression Scale. Potential gray matter correlates of depressive symptoms were analyzed using the Statistical Parametric Mapping software package. Results: Significant results were obtained in the prodromal AD group only. In that group, depressive symptoms were related to atrophy in the left precentral gyrus (Brodmann area 6) (p≤0.01, FWE corrected). Conclusion: Our results, added to the existing literature, suggest that dysfunction in left-sided, cognitively and functionally salient, cortical regions along with relative preservation of deficit awareness, provided by the right hemisphere, explain depressive symptoms in the initial clinical stages of AD.